PROJECT SUMMARY Amblyopia is a disorder of visual acuity caused by disruptions in vision during an early critical period. The neural basis for amblyopia has predominantly been studied using ocular dominance plasticity. I recently discovered a distinct critical period for high spatial acuity in visual cortex that precedes the ocular dominance critical period. In this proposal, I aim to take advantage of this key insight and dissect out the specific neural circuits responsible for high acuity responses. Using in vivo calcium imaging of large populations of cortical neurons, I will determine the development of high spatial frequency tuned neurons in mouse visual cortex. I hypothesize that the emergence of high acuity vision involves the emergence of a subpopulation of high spatial frequency tuned neurons. Previously, I showed inhibitory interneuron transplantation induces recovery of high acuity vision in amblyopic mice. I will use a calcium imaging to determine whether our previously reported transplant induced restoration of acuity in amblyopic mice involves the restoration of high spatial frequency tuned neurons. If successful, this work will be provide insight into the neural circuits underlying high acuity vision and may lead to new insight for amblyopia research.!